考虑钢渣表面特征的沥青混凝土水稳定性改善研究

Research on improvement of moisture stability of asphalt concrete considering surface characteristics of steel slag

钢渣经过水洗和陈化处理后可作为粗集料铺筑沥青路面。但钢渣表面有杂质粉尘包裹,高压水洗难以去除,陈化后钢渣表面依然对沥青混凝土水稳定性有显著影响。为促进钢渣在工程中应用,本研究以生产线大批量制备的工程用钢渣集料为研究对象,采用SBS改性沥青及硅酸盐水泥填料调整沥青胶浆的组成来增强钢渣与沥青胶浆的粘附,改善钢渣沥青混凝土的水稳定性。首先采用XRD对钢渣及钢渣表面矿物相成分分析,从理论上验证改善方案的可行性;然后对沥青胶浆包裹的钢渣集料进行水煮试验,分析改善措施对粘附性的提升效果;最后对钢渣沥青混凝土进行冻融劈裂试验和浸水马歇尔试验,确定其水稳定性变化。结果表明,改善措施能使水稳定性能得到改善,建议SBS改性沥青和硅酸盐水泥复合使用。

Steel slag can be used as coarse aggregate for asphalt pavement after being washed and aged.However,the surface of steel slag is wrapped with dust,which is difficult to remove by high-pressure water washing,and the aged steel slag surface still has a significant effect on the moisture stability of asphalt concrete.This paper takes the massproduced steel slag aggregate for engineering in production line as the research object.And SBS modified asphalt and Portland cement filler are used to adjust the composition of asphalt mastic,enhance the adhesion between steel slag and asphalt mastic,and improve the moisture stability of steel slag asphalt concrete.Firstly,XRD test is used to analyze the mineral phase composition of the steel slag and steel slag surface to theoretically verify the feasibility of the improvement method.Then the steel slag aggregate wrapped with asphalt mastic is subjected to boiling test to analyze the effect of the improvement method on the adhesion.Finally,freeze-thaw splitting test and immersion Marshall test are conducted on the steel slag asphalt concrete to determine the changes of its moisture stability.The results show that this improvement method can improve the moisture stability,and it is recommended to use SBS modified asphalt and Portland cement in combination.